Never, ever quit

“Genius is one percent inspiration, ninety-nine percent perspiration.” — Thomas Edison

Most incidents of success amount to little more than extraordinary persistence; he who fights the longest often wins. The inverse, however, is absolute: if you quit, you can never win. Therefore, don’t quit. Always push yourself to continue.

But do not hold on to battles blindly — quit unwise undertakings: if a plan does not make sense, abandon it; if an objective is not useful, withdraw; if a relationship is tanking, pull out. What matters is not the battle, but that you never give up the war.